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rgleason · 29-03-2018, 15:42

Sean has another plugin.

Quote:

pypilot Plugin for OpenCPN
OpenCPN can communicate with pypilot already via nmea to receive compass heading, and to autopilot, and the plugin is not strictly required. The plugin allows for configuration and tuning of the autopilot in ways not possible through basic nmea0183 messaging. The plugin also allows for graphical overlays of the autopilot settings directly onto the chart.

Running VDR files with ECRMB, ECRMC and ECAPB it doesn't appear that the AP is recieving, but I may have some misconfiguration.
The plugin compiles and Opencpn does not seem to crash.

Available to Beta Testers here
https://github.com/rgleason/pypilot_pi/releases

seandepagnier · 29-03-2018, 17:07

you need to have a working pypilot autopilot server running (openplotter or tinypilot) to use this plugin

rgleason · 22-04-2018, 14:48

Sean, the video is a good demo, I'll add it to the plugin wiki documentation. Are you using a wiper motor like this Dodge Ram Front Windshield Wiper Motor or I suppose a wiper motor from a junkyard would also work? It uses a small motor to generate a lot of force to move a wiper blade.

1. Get one with permanent magnets? (early magnets years ago got weak, but not so now. Permanent magnets got better and stronger. and wiper motors were changed to have permanent magnets.) Ones with permanent magnets are more efficient and use less power.
2. Worm gear, with shaft back and forth.
3. Autopark switch and separate power source to bring the motor back to home (this would be the centerline of the boat?) --So maybe the park switch needs to be moved 90 degrees?
4. DC Motor can be changed into a generator very easily (dead shorts are tough on the generator). The autopark switch turns it into a dead short generator so it stays turned off.
5. Polarity of the magnets stays the same, so if the +/- wires are swapped the motor will reverse and the Autopark switch may get damaged because it is sloped and one way.

Sean wrote:

Quote:

Pelagic autopilot appears to be closed source code... This is not good for sailors ..comparable to a closed plotter like navionics. I remember reading on the blog that the pelagic autopilot never sorted out compass calibration while heeling... Basically, he has inferior algorithms like navionics which uses more cpu and battery power on android compared to opencpn.

So yes, it has rate gyros, he doesn't really use them very well, and the cost for this stuff is tiny compared to what he charges. The linear actuator might be a consideration though.

pypilot is free software like opencpn. It is fully supported by opencpn, and is better supported than any autopilot. It has 2 specialized opencpn plugins designed for it.

You don't need to take my word for it.. For the cost of a raspberry pi, some $4 sensors, and a motor controller you can build, or buy for $75, you could compare the performance driving your pelagic autopilot drive unit. Or just use a windshield wiper motor and a belt to the wheel, or if you have a tiller:

https://youtu.be/ZaLBRRelT-M

Re Simrad TP32

Quote:

..designed more than 20 years ago. Because of poor sensors, they work hard and wear out and consume more power. They don't work in many sea states because of physical swinging compass. The simrad tiller pilot have several design flaws as well. They cost a lot and aren't very good.

Better to get an autopilot with gyros. gyros and other sensors are cheap. You can get better performance reliability and integration with opencpn for a fraction of the cost.

Pypilot thread is here PyPilot
This is a Beta Plugin and the Manual is here

seandepagnier · 23-04-2018, 10:39

The older wiper motors use universal motors and work but you have to rectify one of the coils so that they can reverse direction. They are also less efficient.. so I recommend ones with magnets.

Some wipers have park mechanism. The new ones have a sensor to detect which is easy as I just don't use it. Some older ones have a separate winding that reverses the direction which mechanically parks. I had to defeat this so that the wiper can be driven in both directions.

seandepagnier · 23-04-2018, 10:42

https://youtu.be/au9oZ_-Qces
https://youtu.be/7TdXImMFTZk
https://youtu.be/cxcrgLmPAys
https://youtu.be/z5eVXkQ8Qig
https://youtu.be/ZaLBRRelT-M

rgleason · 05-05-2018, 14:08

Sean has released
pypilot_pi-0.4.000-win32.exe

**hpeer** · 05-05-2018, 14:39

I’ve a question re this pilot.

I have a heavy steel boat with a CPT. Good AP but the problem is the interference from the hull, it distorts the magnetic field pretty badly.

I was wondering if it’s possible to use Pypilot to drive the motor? It seems like a natural match between the two units.

If no one here can help how do I contact Sean to ask him?

**hpeer** · 05-05-2018, 17:06

Well duh!

Sean/Boat Alexander ...hello.

As noted above I’m curious about using the Pypilot as an alternative to the drive motor of a CPT. The CPT Head End has a magnetic compas, you simply rotate a dial to select your course. Except on this Steel boat the magnetic field is badly distorted.

The drive motor has two controls, simply put one controls how closely the motor tries to follow the course, the other the strength of the force to the wheel. The heading info itself seems to be a simple “left/right” input from the compas unit.

There is a separate “remote” that will either (compas more) allow you to vary course up to about 15°, I think of it as a bias or (wheel mode) allow you to turn the wheel directly.

In short, can I use the CPT wheel drive to spin the wheel instead of your motor solution? I’m pretty sure the answer is YES.

If you want to chat privately I’m on Public at Hpeer dot com. I’m cruising the Windwards at the moment.

rgleason · 05-05-2018, 17:37

hpeer, look in the wiki and read it.
Pypilot thread is here PyPilot
This is a Beta Plugin and the Manual is here

Sean explains a lot. Then ask him.

Yes, it can drive your motor I believe.
You could PM him. Cliick on boat_alexandra

barnakiel · 05-05-2018, 18:48

A great effort and the attitude that we do not see too often these days.

So I bump this up so that others can read, build and benefits. And think why sharing beats selling hands down.

Hugs from Martinique to everyone,
b.

seandepagnier · 08-05-2018, 19:13

now testing 30 ton steel boat
https://youtu.be/KQuBwLSMSxI

NahanniV · 09-05-2018, 08:52

Quote:

Originally Posted by boat_alexandra

now testing 30 ton steel boat
https://youtu.be/KQuBwLSMSxI

Is the pilothouse on that boat steel as well ?
Was that a problem ?
Can the heading sensor be installed remote from the Rpi ?

Do you think there could ever be a windows version ?

How close are you to having a higher current driver ?

seandepagnier · 09-05-2018, 09:31

Quote:

Originally Posted by NahanniV

Is the pilothouse on that boat steel as well ?

Yes

Quote:

Was that a problem ?

no

Quote:

Can the heading sensor be installed remote from the Rpi ?

I think up to 2 meters, though there is not much reason to. If you wanted to go further you could possibly add pull up resistors. check the i2c spec

Quote:

Do you think there could ever be a windows version ?

What do you mean windows version?

So far there is an opencpn plugin, and you can use a web browser, so already two ways to control and configure the autopilot from windows.

Do you want to actually run the autopilot on windows without the raspberry pi? It's also very possible as the software is python and completely portable.

Quote:

How close are you to having a higher current driver ?

The smaller controller is designed for 8 amp continuous 30 amp peak. Can probably do 20 amp continous with a fan. Mostly the motor is not running, so it can probably run hydraulic unit in most sea states, but I never tried it.

For the higher controller it's designed for 40 amps continous and 80 amp peak. I have a working prototype, but I am remaking it with an improved design.

I have already a second prototype. It was my goal for today to solder it, and begin testing today, but it will be some time before I can do extensive testing with a large boat with hydraulic pump.

NahanniV · 09-05-2018, 12:34

Quote:

Originally Posted by boat_alexandra

...
Do you want to actually run the autopilot on windows without the raspberry pi? It's also very possible as the software is python and completely portable.
...

Yes. I know people are dismissive of Windows, but, I've had a lot more success using a windows based system as my ships computer than Linux on a Rpi. Otherwise I guess I could just have a dedicated, headless Rpi for the autopilot.

I had planned to install your autopilot as a backup on my boat, but unfortunately it was recently sunk; Perhaps on the next boat.

seandepagnier · 09-05-2018, 13:06

Quote:

Originally Posted by NahanniV

Yes. I know people are dismissive of Windows, but, I've had a lot more success using a windows based system as my ships computer than Linux on a Rpi. Otherwise I guess I could just have a dedicated, headless Rpi for the autopilot.

I would suggest a small headless raspberry dedicated for the autopilot as a starting point. I have developed "tinypilot" os for raspberry zero that runs completely from ram for this purpose.

It is possible to run the autopilot on any operating system as the code is portable Not sure how you would connect the i2c intertial sensors.. so that is likely the only part you would have to do something to resolve.

Quote:

I had planned to install your autopilot as a backup on my boat, but unfortunately it was recently sunk; Perhaps on the next boat.

That is sad.